Ch. 10.2 - The Relative Age of Rocks

Ch. 10.2

The Relative Age of Rocks

Multiple Choice

True or False? The relative age of a rock is an approximate age that is close to the real age, but not exact.

• True

• False

Multiple Choice

True or False? The absolute age of a rock is an approximate age that is close to the real age, but not exact.

• True

• False

Multiple Choice

True or False? According to the law of superposition, rock layers at the bottom are younger than rock layers found at the top.

• True

• False

Multiple Choice

True or False? A geologist finds a cliff where the edges of several different rock layers can be seen. The bottom layer is the oldest.

• True

• False

Multiple Select

Select each type of clue that helps determine the relative age of rock layers.

• Extrusions/Intrusions

• Faults

• Gaps in the geologic record

• Index Fossils

• Volcanoes

Open Ended

How is an extrusion different from an intrusion?

Multiple Choice

True or False? If an intrusion crosses over an extrusion, the intrusion will be older than the extrusion.

• True

• False

Open Ended

What is an index fossil?

Multiple Choice

The fossil record shows that horseshoe crabs have existed with very little change for about 1 billion years. Would horseshoe crabs be useful as an index fossil?

• Yes, because they were around for a very long time

• No, because horseshoe crabs can never be used as index fossils

• No, because they were around for TOO LARGE of an amount of time

• Yes, because horseshoe crabs can always be used as index fossils